<?php
/*
 *  $Id: Mysql.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Connection_Mysql
 *
 * @package     Doctrine
 * @subpackage  Connection
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
 * @version     $Revision: 7490 $
 * @link        www.doctrine-project.org
 * @since       1.0
 */
class Doctrine_Connection_Mysql extends Doctrine_Connection_Common
{
	/**
	 * @var string $driverName                  the name of this connection driver
	 */
	protected $driverName = 'Mysql';

	/**
	 * the constructor
	 *
	 * @param Doctrine_Manager $manager
	 * @param PDO|Doctrine_Adapter $adapter     database handler
	 */
	public function __construct(Doctrine_Manager $manager, $adapter)
	{
		$this->setAttribute(Doctrine_Core::ATTR_DEFAULT_TABLE_TYPE, 'INNODB');
		$this->supported = array(
                          'sequences'            => 'emulated',
                          'indexes'              => true,
                          'affected_rows'        => true,
                          'transactions'         => true,
                          'savepoints'           => false,
                          'summary_functions'    => true,
                          'order_by_text'        => true,
                          'current_id'           => 'emulated',
                          'limit_queries'        => true,
                          'LOBs'                 => true,
                          'replace'              => true,
                          'sub_selects'          => true,
                          'auto_increment'       => true,
                          'primary_key'          => true,
                          'result_introspection' => true,
                          'prepared_statements'  => 'emulated',
                          'identifier_quoting'   => true,
                          'pattern_escaping'     => true
		);

		$this->properties['string_quoting'] = array('start' => "'",
                                                    'end' => "'",
                                                    'escape' => '\\',
                                                    'escape_pattern' => '\\');

		$this->properties['identifier_quoting'] = array('start' => '`',
                                                        'end' => '`',
                                                        'escape' => '`');

		$this->properties['sql_comments'] = array(
		array('start' => '-- ', 'end' => "\n", 'escape' => false),
		array('start' => '#', 'end' => "\n", 'escape' => false),
		array('start' => '/*', 'end' => '*/', 'escape' => false),
		);

		$this->properties['varchar_max_length'] = 255;

		parent::__construct($manager, $adapter);
	}

	/**
	 * Overrides connect Method, to add specific attributes
	 * PDO emulate prepares is required to avoid bugs on mysql < 5.1
	 * when trying to prepare DROP DATABASE or CREATE DATABASE statements
	 *
	 * @see Doctrine_Connection :: connect();
	 * @return boolean connected
	 */
	public function connect()
	{
		$connected = parent::connect();
		$this->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);

		return $connected;
	}


	/**
	 * returns the name of the connected database
	 *
	 * @return string
	 */
	public function getDatabaseName()
	{
		return $this->fetchOne('SELECT DATABASE()');
	}

	/**
	 * Set the charset on the current connection
	 *
	 * @param string    charset
	 */
	public function setCharset($charset)
	{
		$query = 'SET NAMES ' . $this->quote($charset);
		$this->exec($query);
		parent::setCharset($charset);
	}

	/**
	 * Execute a SQL REPLACE query. A REPLACE query is identical to a INSERT
	 * query, except that if there is already a row in the table with the same
	 * key field values, the REPLACE query just updates its values instead of
	 * inserting a new row.
	 *
	 * The REPLACE type of query does not make part of the SQL standards. Since
	 * practically only MySQL implements it natively, this type of query is
	 * emulated through this method for other DBMS using standard types of
	 * queries inside a transaction to assure the atomicity of the operation.
	 *
	 * @access public
	 *
	 * @param string $table name of the table on which the REPLACE query will
	 *  be executed.
	 * @param array $fields associative array that describes the fields and the
	 *  values that will be inserted or updated in the specified table. The
	 *  indexes of the array are the names of all the fields of the table. The
	 *  values of the array are also associative arrays that describe the
	 *  values and other properties of the table fields.
	 *
	 *  Here follows a list of field properties that need to be specified:
	 *
	 *    value:
	 *          Value to be assigned to the specified field. This value may be
	 *          of specified in database independent type format as this
	 *          function can perform the necessary datatype conversions.
	 *
	 *    Default:
	 *          this property is required unless the Null property
	 *          is set to 1.
	 *
	 *    type
	 *          Name of the type of the field. Currently, all types Metabase
	 *          are supported except for clob and blob.
	 *
	 *    Default: no type conversion
	 *
	 *    null
	 *          Boolean property that indicates that the value for this field
	 *          should be set to null.
	 *
	 *          The default value for fields missing in INSERT queries may be
	 *          specified the definition of a table. Often, the default value
	 *          is already null, but since the REPLACE may be emulated using
	 *          an UPDATE query, make sure that all fields of the table are
	 *          listed in this function argument array.
	 *
	 *    Default: 0
	 *
	 *    key
	 *          Boolean property that indicates that this field should be
	 *          handled as a primary key or at least as part of the compound
	 *          unique index of the table that will determine the row that will
	 *          updated if it exists or inserted a new row otherwise.
	 *
	 *          This function will fail if no key field is specified or if the
	 *          value of a key field is set to null because fields that are
	 *          part of unique index they may not be null.
	 *
	 *    Default: 0
	 *
	 * @return integer      the number of affected rows
	 */
	public function replace(Doctrine_Table $table, array $fields, array $keys)
	{
		if (empty($keys)) {
			throw new Doctrine_Connection_Exception('Not specified which fields are keys');
		}

		$columns = array();
		$values = array();
		$params = array();
		foreach ($fields as $fieldName => $value) {
			$columns[] = $table->getColumnName($fieldName);
			$values[] = '?';
			$params[] = $value;
		}

		$query = 'REPLACE INTO ' . $this->quoteIdentifier($table->getTableName()) . ' (' . implode(',', $columns) . ') VALUES (' . implode(',', $values) . ')';

		return $this->exec($query, $params);
	}
}